Inside the minds of Trump voters: do they really all believe climate change was invented by China?

Republican rhetoric, communist hoax and voter psychology; Geraldine Satre Buisson, a PhD student on the Science and Solutions for a Changing Planet Doctoral Training Partnership at Imperial College London, looks across the pond at the United States’ attitudes towards climate change.

We’ve all seen the tweets. Donald Trump thinks that climate change is a hoax created by China. It is often cited by those who are concerned with his administration’s position on climate change, but do Trump supporters really adhere to these views, and, crucially, how might their political persuasions lead them to ignore the overwhelming scientific evidence for climate change?

The people who seem concerned may be justified: Trump’s campaign promises include the withdrawal from the Paris Agreement, the elimination of the Obama Administration’s Clean Power Plan (which, among other things, included steps to phase-out coal power plants) and the development of infrastructure for shale oil and gas. His first weeks in office have not provided much reassurance: his administration imposed a temporary media blackout to the Environmental Protection Agency (EPA) and nominated a man who once described himself as a “leading advocate against the EPA’s activist agenda,” to head said EPA, amid rumours that the agency could be abolished altogether.

There was a time when Conservatism and conservation went hand in hand fairly well. The National Park Service was created under Republican President Woodrow Wilson in 1916 (it today ensures the protection of over 1.2 million km² of land – the largest such area in the world). The EPA was created under President Nixon in 1970, who, in his own words made “an exception to one of [his] own principles. That, as a matter of effective and orderly administration, additional new independent agencies normally should not be created,” because there were simply no better options.

A widening rift

So, when did that change? A study conducted at Oklahoma State University shows that the environment has become an increasingly partisan issue since the 1980s (see this article summarising some of the key findings). The annual percentage of pro-environment votes cast by Republican representatives in the past thirty years has drastically declined (from about 35% in 1980 to below 5% in 2015), just as pro-environment votes by Democrats have increased (from about 55% in 1980 to 90% in 2015, see Figure 1).

These differences in voting patterns in Congress reflect a widening gap in public opinion on environmental issues, and especially on climate change. In 2001, 53% of Republicans believed that the changes in the Earth’s temperature over the twentieth century were due to human activities, against 70% of Democrats. That difference more than doubled in the following 15 years, with Republican belief in man-made climate change dropping to 43% in 2016, while Democrats’ increased to 84% (see Figure 2).

When politics influence reasoning

Refuting climate change might seem, therefore, to be becoming a core element of Republican identity. One reason for this may lie in what Dan Kahan, Professor of Psychology leading the Cultural Cognition Project at Yale, calls “politically motivated reasoning”. He compared, over the course of several studies, people’s numeracy and ability to understand scientific studies. Participants were first asked to answer generic math questions, and then quantitative questions related to studies on “neutral” topics (like skin rashes) and controversial topics (like gun violence). The expectation was that people who answered more accurately at generic math questions would be better equipped to understand scientific evidence on controversial topics, regardless of whether the evidence supported their political opinions.

He found instead that people who had scored better at the math questions were more likely to answer wrong when asked questions concerning topics that did not agree with their political beliefs than people who had scored worse at the generic math test. His conclusion was that individuals appear to apply rational thinking to serve their existing beliefs.

Thus, it is not necessarily the case that people deny the existence of climate change because they do not understand the science that supports it. Rather, if they associate the issue with political views they oppose, then being exposed to more evidence will only reinforce their rejection of it. This kind of phenomenon is particularly true of two-party systems where the “with us or against us” mentality is most prominent (George Washington is famously cited as an opponent of the party system because he feared such partisan entrenchment would happen).

But, a recent Yale survey seems to temper this rather gloomy vision of an ever-deepening political entrenchment. The Yale Program on Climate Change Communication has been monitoring US citizens’ opinions on climate change since 2004. Following the election, it found that about half of Trump voters (49%) “think global warming is happening,” while fewer than one in three (30%) “think global warming is not happening.”

So, when President Trump says that “nobody really knows if climate change is real”, what he should actually be saying, is: “most people including half of those who voted for me, know it is real, but it’s not in my economic and political interest to do anything about it”.